This invention relates to a method for closing off at least one tunnel extending across the width of a folding curtain, after a strengthening rod has been introduced into this tunnel on the one hand, and a folding curtain comprising at least one tunnel extending across the width of the curtain, which has been provided with a strengthening rod according to the invention on the other hand.
Folding curtains are often used as a decoration. A usual folding curtain is hanging straight down when it has been lowered completely. In order to obtain a curtain that is more tightened when it is lowered, the fabric is provided with tunnels that are stitched at different distances and extend across the full width of the curtain. Then, weightings, the so-called strengthening rods (or baleens) are introduced into the said tunnels mentioned above.
In order to be able to give the folding curtains a high quality, a few things are important:                tunnels stitched in straight lines;        the possibility to remove the strengthening rods from the curtains easily, so that they may be cleaned;        strengthening rods ensuring a constant tension, so that the curtains will get a nice and straight aspect.        
In order to make the tunnels perfectly straight, use is made of an automatic tunnel stitching device.
In order to be able to remove the strengthening rods from the curtains in a simple manner, it is known to provide an opening, more specifically a buttonhole on the lower side of the tunnel.
However, when a tunnel is provided with a buttonhole by means of the automatic tunnel stitching device, the following will occur: as the number of tunnels of each curtain will increase, the buttonhole will slide upwards when stitching the tunnels, because of which the buttonhole will be no longer in the lower part of the tunnel but on the upper part, so that it will become visible. This means a decrease in quality of the curtain, therefore no buttonholes may be provided when an automatic stitching device is used. It is only possible to make the perfect use of this machine if the tunnel is closed by stitching, but then it becomes impossible to remove the strengthening rods from the curtain for cleaning purposes.